MS Professor Powell speaking:- (natural sound) "These pieces of equipment are to be attached to the tail of a balloon, which is going to rise to a height of about 20 miles into the atmosphere. The most important features are these radio transmitters which tell us the height of the balloon, and particularly these photographic plates, these plates enable us to study, what we call cosmic radiation. This radiation, the cosmic radiation, consists of very fast charged particles the particles are so fast that there are able to penetrate this tin box and go right to the photographic plates contained in it. We get the plates back when they are cut off of in a parachute and then we develop them and look at them under a microscope, we are then able to find out particular things that these particles have done just as you can detect the traces of animals by the tracks they leave in moving over snow so we can find out, we can see the traces of these animals of the world of atomic physics. We are, as it were, experienced hunters of the particles of the cosmic radiation".